package zh.codegym.task.task04.task0412;

/* 
正数和负数
*/

import java.io.*;
import java.util.Scanner;

public class Solution {
    public static void main(String[] args) throws Exception {
        //在此编写你的代码
        Scanner scanner = new Scanner(System.in);
        int number = scanner.nextInt();
        System.out.println(  (number < 0) ? ++number  : (number > 0 ) ? number * 2 : number);

    }

}